1. Field of Invention
This invention is a shutter system for blocking the path of light of a high intensity discharge lamp. More particularly, the invention is an adjustable shutter system which blocks the path of light of a high intensity discharge lamp while also absorbing light from the lamp and discharging heat created by the light away from the system.
2. Prior Art
In theater lighting or lighting for sporting events, it is often desirable to partially or totally block the path of light from spot lights to achieve varied lighting effects. Often during these events, it is also desirable to completely block the path of light and thereby create a darkened atmosphere for short periods of time. With some lighting systems, this effect is achieved by merely turning the lights off and back on. However, because of their structure and composition, it is difficult to turn off and quickly turn back on certain types of lighting, such as high intensity discharge lights. With this type of lighting source, once the system is turned off, there is generally a delay, sometimes of several minutes, to re-energize the system before it can be turned back on. Thus, it is undesirable to extinguish high intensity discharge lighting at any time during such an event. Other methods of blocking the path of light must then be used to achieve the desired darkened atmosphere.
Several systems currently exist which block the path of light of a light source. One system commonly used is an iris-type shutter system as shown, for example, in U.S. Pat. No. 4,458,303. Another type of shutter system uses a series of shutter blades which are extended or withdrawn from the path of light to block or partially block the path of light. By fully extending the blades, the path of light of the lighting system can be completely blocked. A number of these type of shutter systems are disclosed, for example, in U.S. Pat. Nos. 2,695,547, 4,210,955 and 5,510,969.
In addition to blocking the path of light, it is often desirable to defuse the light, thus changing its intensity or color. Light diffusing systems also often utilize a system of shutters that partially or totally block the path of light of a lighting system. See, for example, U.S. Pat. No. 4,052,607. In addition, U.S. Pat. No. 3,555,264 discloses a shutter system utilizing hinges which block portions of the light spectrum from escaping from a light source, such as white or infrared light.
A more complicated mechanical system for diffusing light is disclosed in U.S. Pat. No. 4,972,306. In this system a tambour-type panel of sections is attached to a track system. The panels are moved by this track system in front of the path of light. By blocking the path of light with different types of filter panels, the spectrum of the light which escapes the system is modified.
With lighting systems such as high intensity discharge lights, it is important not only to block the path of the light, but also to prevent heat buildup within the high intensity discharge light system while the path of light is being partially or totally blocked. Modern high intensity discharge lights operate at high temperatures, as high as 750.degree. F. If a shutter system merely blocks the path of light of a high intensity discharge light, heat created by the lighting system is trapped within the system resulting in serious heat build up which reduces the effectiveness and life expectancy of the system. In addition, these high temperatures increase the likelihood of fire or other heat-related damage to the lighting system.
It is therefore an object of this invention to disclose a shutter system for use with a high intensity discharge lighting system.
It is a further object of this invention to disclose a shutter system for use with a high intensity discharge lighting system which substantially blocks the path of light from a high intensity discharge lighting system.
It is a still further object of this invention to disclose a motorized shutter system for use with a high intensity discharge lighting system which is capable of both blocking the discharge of light and permitting full discharge of light from the high intensity discharge light.
It is a still further object of this invention to disclose a lighting and shutter system which combines a motorized shutter system to prevent light from escaping the high intensity discharge light system with a heat absorbing cover which absorbs and discharges heat away from the light system.
These and other objects and features of the present invention will become apparent to those skilled in the art from consideration of the detailed description, drawings and claims. The description along with the accompanying drawings provides a selected example of construction of the device to illustrate the invention.